1. Field of the Invention
The present invention relates to an electrical actuator for forming the shed in a weaving loom, particularly for controlling the harness cords of a weaving system of the Jacquard type or the frames of a dobby, and to a process for manufacturing such an actuator. The invention also relates to a weaving system comprising such an actuator, and to a weaving loom equipped with such a system.
2. Brief Description of the Related Art
In weaving systems of the Jacquard type, it is known to drive, in phase opposition, two frames each bearing a plurality of griffes or horizontal knives 10 adapted to displace, vertically, hooks connected to the harness cords by a pulley or block mechanism. Mechanical or electromechanical devices are provided to immobilize these hooks along their vertical stroke. This known type of device necessitates considerable power for moving the griffe frames, which power is furnished by the drive shaft of the weaving loom, this leading to said loom being overdimensioned.
It is also known to use a rotating motor such as a step motor or a servomotor to control a small cord belonging to a weaving loom, linearly. Taking into account the large number of electric motors used in the weaving system associated with a weaving loom, a number which may attain and even exceed 10 000, these motors must be of minimum space requirement and cost, while having considerable reliability. In particular, winding of the conducting wire must be effected rapidly while guaranteeing a sufficient level of quality. In addition, the stator must have dimensions adapted to those of the rotor which, in order to optimize its inertia, must have a diameter which is as small as possible. Finally, the manufacturing tolerances of the metal plates constituting the stacks forming the stators must not hinder manufacture thereof nor reduce their yield.
It is an object of the present invention to propose an electrical rotating actuator adapted to control displacement of one or more harness cords, which is compact and simple to manufacture.